The present invention relates to storage devices and has particular application to high capacity, high performance, low profile storage arrays.
Heating is a constant and significant problem in digital data systems. The failure rates of many electronic components increase as operating temperatures rise. The problem is compounded by the use of ever more densely packed circuit boards, which increase local heating, and by more compact, lower profile devices which tend to restrict the airflow available for heat dissipation, e.g., for heat transfer cooling.
Most often, the components of digital data systems are cooled by airflow. Fans are typically used to push or pull air from one side of a chassis, across the enclosed components, and out the other side of the chassis. Thus, for example, the chassis of a typical digital data processor may include intake and/or exhaust fans, and may include additional fans on specific components or assemblies, such as power supplies, central processing units, and other heat-sensitive and heat-generating parts to further enhance cooling locally. While these solutions have proven adequate to date, there remains a need to provide for the cooling of even more powerful, more densely packed and/or more compact systems.
This need is particularly acute for web servers, network servers and other high capacity storage systems, in which a great number of essentially simultaneous data accesses and data transfers must be carried out with a data bank physically located at a specific and limited location, e.g., a computer room or a terminus or node of a broadband communications system. The hardware for these arrays typically comprise multiple disk drives, CDROM drives, or other magnetic, optical or optical-magnetic storage devices (e.g., hereinafter collectively referred to as xe2x80x9cdrives,xe2x80x9d xe2x80x9cstorage devices,xe2x80x9d xe2x80x9cstorage units,xe2x80x9d and so forth, except where otherwise evident from context) arranged in a single chassis, with multiple such chassis stacked in a single rack; to provide an array in which over one hundred drives occupy less than five or six square feet of floor space.
The chassis used in conventional high capacity storage systems are at least 3U, or 5xc2xd inches, in height. Their depths and widths are selected, typically, for mounting in 19 inch equipment racks. In such configurations, twelve drives are mounted on their sidesxe2x80x94like plates xe2x80x9cstackedxe2x80x9d side-by-side in a dishwasher. These 3U chassis, in turn, may be mounted in a stack ten or twelve high on a rack.
While useful in many applications, storage arrays that utilize 3U chassis do not meet the needs of all users who require high density storage capacity.
One object of the present invention is to provide an improved storage devices and, more particularly, improved storage arrays.
A more particular object is to provide such apparatus and methods as can be particularly adapted to web servers and other data processing apparatus that are compact of design and/or prone to overheating.
A still further object is to provide such apparatus and methods as can be implemented at low cost.
A still further object of the invention is to provide such apparatus and methods as can be adapted to pre-existing equipment, as well as designed for use in new equipment.
One or more of the foregoing objects are met by the present invention which provides, in one aspect, a low profile, high density storage array having a plurality of drives mounted xe2x80x9cflatxe2x80x9d (as opposed to on their xe2x80x9csidesxe2x80x9d) within a chassis. The drives are spaced apart from a floor (or other wall) of the chassis on which they are mounted, so as to define a passage for cooling airflow. In accordance with one aspect of the invention, this spacing is provided by a support (e.g., legs, platform or a xe2x80x9csledxe2x80x9d) on which each drive is mounted that defines the airflow passage and that facilitates insertion and removal of the drive from the chassis.
In another embodiment, a storage array as described above comprises a plurality (e.g., eight or more) of drives each mounted on a respective support that, in turn, is disposed on a floor of the chassis. The support elements and/or respective drives are removably coupled to the chassis.
Coupling is provided, according to further aspects of the invention, by a cam-like levers which facilitate pushing the drives into and/or pulling them from physical and electrical engagement with the array and its electrical circuits (e.g., buses). Pairs of these levers can be provided for each drive, allowing the drive to be easily jockeyed into or out of engagement with the chassis and its electrical connectors without pin damage, despite the otherwise limited room for movement in a densely packed 1U chassis.
In yet another embodiment, the drives are removably attached to the support elements.
These and other aspects of the invention are evident in the drawings and in the discussion that follows.